During endoscopic surgical procedures such as a peroral endoscopic myotomy or a submucosal tunneling endoscopic resection, a submucosal tunnel may be formed in a portion of the gastrointestinal wall (e.g., the esophagus, the stomach, etc.) using an endoscope. The tunnel is normally formed by dissecting the submucosal layer (between the mucosa layer and the muscle layer) of the gastrointestinal wall using an electrosurgical knife that extends through a channel within the endoscope. Manipulating the knife to a proper position within the channel of the endoscope can be challenging. In addition, it may be desirable in many different surgical procedures to sever or dissect a target portion of a native tissue from a remaining portion.